sustainability Article San Antonio 360: The Rise and Decline of the Concentric City 1890–2010 Ian Caine 1,*, Rebecca Walter 1 and Nathan Foote 2 1 Department of Architecture, University of Texas at San Antonio, San Antonio, TX 78249, USA; [email protected] 2 Bloustein School of Planning and Public Policy, Rutgers University, New Brunswick, NJ 08901, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-210-458-8771 Academic Editor: Vincenzo Torretta Received: 22 February 2017; Accepted: 12 April 2017; Published: 19 April 2017 Abstract: This paper catalogs the suburban expansion of San Antonio, Texas by decade between the years 1890 and 2009, a time frame that saw the city reorganize its morphological structure four times. The city inhabited a 36-square mile grid until the late nineteenth century; expanded radially along streetcar lines during the early twentieth century; grew concentrically along automotive ring roads during the mid-twentieth century; and has assumed a polycentric organization within the past two decades. This research places San Antonio’s recent demographic and geographic boom into historical perspective, utilizing construction completions in host Bexar County to answer the following question: how did the form, location, and type of suburban growth shift over 120 years? The research reveals three trends: first, that historically concentric growth patterns began to assume a polycentric configuration in the late twentieth century; second, that patterns of centrifugal expansion began to accelerate dramatically during the same time period; and third, that the relative increase of multifamily completions has surpassed that of single-family completions in five of the last six decades. These findings suggest that the City of San Antonio, in order to establish a sustainable growth model, must prioritize the opportunities and constraints associated with polycentric suburban expansion. Keywords: suburban growth; GIS; San Antonio; Texas; kernel density; New Suburbanism 1. Introduction The topic of suburban expansion is timely for the City of San Antonio, Texas. With an estimated population of 1,469,845, San Antonio currently ranks the second largest city in the state and seventh largest in the United States [1]. The city will add 500,000 jobs and 500,000 units of housing by 2040, testament to a strong and diverse economy built on healthcare, education, military and tourism. All of this in a city that added 430,000 people in the last ten years [2]. This growth will increase the population of host Bexar County by 65%, with much of the population influx occurring within the San Antonio city limits [3]. This demographic expansion would likely lead to significant geographic expansion. The city’s current footprint covers 467 square miles, at the relatively low residential density of 3017 people per square mile [3] (Figure1). Sustainability 2017, 9, 649; doi:10.3390/su9040649 www.mdpi.com/journal/sustainability Sustainability 2017, 9, 649 2 of 16 Sustainability 2017, 9, 649 2 of 17 Figure 1. Urban development in Bexar County, 2010. Figure 1. Urban development in Bexar County, 2010. OurTable research 1. Number is already of Construction registering Completions, the impact Bexar of this County growth, 1890 measured–2009. Source: as aBexar function County of both constructionProperty completionsAppraiser 2015. and developed land area. A comparison of the 1990s and 2000s, for example, shows a 165% increase in construction completions and a 185% increase in developed land area Avg. Distance (Table1). This data reveals the largestBuildings relative increasesDeveloped during the post-WWII period and the largest Decade from Center total increases ever. (Count) Land (Acres) (Miles) Table 1. Number1890s of Construction 438 Completions, Bexar17 County 1890–2009.2.8 Source: Bexar County Property Appraiser1900s 2015. 2393 100 2.8 1910s 5148 188 2.6 Decade Buildings1920s (Count) 19,392 Developed Land681 (Acres) Avg.2.9 Distance from Center (Miles) 1930s 18,830 643 3.7 1890s 438 17 2.8 1940s 47,824 1663 4.2 1900s 2393 100 2.8 1950s 69,709 2929 5.5 1910s 5148 188 2.6 1920s1960s 19,392 64,887 6813622 7.8 2.9 1930s1970s 18,830 80,062 6434849 9.9 3.7 1940s1980s 47,824 91,343 16635720 11.0 4.2 1950s1990s 69,709 76,727 29294452 12.2 5.5 1960s2000s 64,887 126,421 36228242 12.8 7.8 1970sTotal 80,062 603,174 484933,106 9.9 1980s 91,343 5720 11.0 1990s 76,727 4452 12.2 The2000s dramatic expansion 126,421 of population and 8242 land area has prompted city planners 12.8 to advance a series of recent policy efforts including a comprehensive master plan, transportation plan, and Total 603,174 33,106 sustainability plan. These documents outline a plan for growth through 2040. The explicit goal of the Comprehensive Plan, passed in 2016, is to determine the direction and form of future physical growth,The dramaticdistribute expansion the projected of population population, and landand areaguide has infrastructural prompted city investment planners to advance[3]. The aComprehensive series of recent Plan policy recognizes efforts includingthat economic a comprehensive activity in San master Antonio plan, is distributed transportation widely plan, across and sustainability13 regional no plan.des, Thesenine existing documents and outlinefour emerging a plan for, which growth together through account 2040. The for explicit half of goal the ofcity’s the Comprehensiveemployment and Plan, non passed-residential in 2016, development is to determine since the the direction year 2000 and [3]. form The ofComprehensive future physical Plan growth, also distributerecommends the further projected investment population, in these and guidenodes, infrastructuralwith the hope of investment transforming [3]. Thethem Comprehensive into mixed-use Planactivity recognizes centers that[3]. The economic city is activityalso preparing in San Antonio an $850 is-million distributed-dollar widely bond acrosscampaign 13 regional to fund nodes,major nineinfrastructure existing andprojects. four Together, emerging, these which two together policy efforts account will for go halfa long of way the toward city’s employment determining andSan Sustainability 2017, 9, 649 3 of 16 non-residential development since the year 2000 [3]. The Comprehensive Plan also recommends further investment in these nodes, with the hope of transforming them into mixed-use activity centers [3]. The city is also preparing an $850-million-dollar bond campaign to fund major infrastructure projects. Together, these two policy efforts will go a long way toward determining San Antonio’s ability to sustain existing environmental, financial, and infrastructural systems in the face of unprecedented local growth. Our research catalogs the history of suburban expansion in San Antonio in order to help policy-makers and residents make more critically informed choices about where and how to grow. We begin the research in the year 1890, which marks the first time that the city began large-scale expansion beyond its original 36-square mile colonial grid. The ensuing 120 years saw San Antonio transform itself multiple times; stretching its historical footprint in a linear fashion along streetcar routes, multiplying growth in a concentric fashion along automotive ring-roads, and eventually assuming the complex polycentric footprint that the city exhibits today. While the origins of suburban development in the United States date to the early nineteenth century, it was not until the second half of the twentieth century that suburbs fully eclipsed central cities as the primary locale for residential and economic development in U.S. cities. Mieszkowski and Mills [4] note that between the years 1950 and 1990, the percentage of residents living within central cities, as opposed to larger metropolitan statistical areas, declined from 57% to 37%, while the percentage of jobs declined from 70% to 45%. Wheeler [5] uncovers similar trends in his study of six metropolitan areas in the U.S., revealing that 88% of their total metropolitan land area was developed after 1940, a time period when suburban morphologies achieved prevalence. Farris [6] locates a similar disparity in studies of 22 major central cities, finding that during the 1990s they netted only 5.2% of total new metropolitan housing permits. The ascendance of suburban morphologies during the second half of the twentieth century has generated continuous and widespread disdain from planners, policy-makers, and architects. Early detractors like Peter Blake [7] critiqued suburbia on largely aesthetic terms, lamenting the negative visual impact of billboards and power lines on previously countryside views. More recently, opponents have focused their ire on the professed social and environmental deficiencies of suburban development [8,9]. This critical discourse, impressive in its breadth, depth, and diversity, generally falls under the rubric of New Urbanism or Smart Growth [9–12]. These related movements are bound by a series of design and policy prescriptions, many of which seek to recapture the best qualities of the pre-automotive city. Some of the most prevalent strategies include increasing population densities, re-introducing street grids, expanding mixed-use zoning, and investing in mass transit networks. The last decade, however, has seen attitudes towards suburbia shift as critics have increasingly come to accept the inherent form and logic of suburban landscapes. Robert Bruegman [13] constructs a powerful historical argument for this position, reminding us that the geographic decentralization that defines suburban locales is not unique to post-war U.S. cities. In fact, even ancient cities like Babylon, Ur, and Rome included transitional or suburban zones, which by definition fall somewhere between urban and rural conditions. Joel Kotkin [14] similarly contends that the expanded decentralized structure of U.S. post-war suburbs is fully capable of accommodating growth in an environmentally and socially productive manner. According to Kotkin, the proper role of policy-makers and designers is therefore to facilitate further growth through more productive policy and formal arrangements within the existing suburban structure.